Re assignment of the sheet metal rules for the resulting component will not be possible.
Fusion 360 sheet metal flat pattern.
Link to vote for improved sheet metal tools in fusion.
To do that create the sheet metal part from scratch in fusion 360.
How to make flat patterns for rolled sheet metal designs.
An example of the procedure for a sat file is presented in the screencast below.
Sheet metal bodies with multiple radii curves or arcs in the sketch.
Create a small flat tab somewhere on your design that can be cut off during manufacturing and use that as the stationary face for the flat pattern.
When exporting a dxf flat pattern in fusion 360 sheet metal an error occurs.
Select the stationary face.
Go to modify flat pattern.